Blow molded pallet with pre-formed inserts

ABSTRACT

A pallet system includes a pallet body. The pallet body is formed from a first, independently formed first portion and a second blow molded second upper portion insert molded to the first portion. The pallet body may have two to eight recesses for forklift truck fork access. The second upper portion has a generally rectangular surface for carrying loads. The portions may have anti-skid properties, for example, a knurled topside surface or rubber coated bottom. At least one foot is attached to the second upper portion by insert molding. At least one runner may be attached to each foot to form part of the first portion. At least one stringer is attached to each runner to add further stability to the pallet. The runners and feet have channels or protruding members to effectively mate with the second upper portion. The system may also have top cap and tie members to affix the cap to one or more pallet bodies as well as high-friction inserts to permit the pallet from sliding on a surface or objects from sliding on the pallet.

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application is a continuation-in-part of U.S. applicationSer. No. 10/368,284, filed Feb. 17, 2003.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates in general to the field ofplastics. More particularly, the present invention relates to a palletsystem and a pallet apparatus and a method of pallet manufacturing.Specifically, one preferred embodiment of the present invention relatesto blow molding a first pallet piece and then inserting it into anothermold to join it to a second blow molded pallet piece.

[0004] 2. Discussion of the Related Art

[0005] Pallets are used for transporting and storing various types ofcargo throughout the world. Therefore, it is important for a pallet tobe lightweight, compact and strong. Traditionally pallets were made ofwood. However, plastic pallets are now being used with increasedfrequency, as they are lightweight, generally stronger, do not absorbmoisture, and they can be cleaned and disinfected which is important inparticular for the food industry. One disadvantage of plastic pallets isthat they tend to break up with continued use over time. Therefore, forthese and other various reasons it is important that plastic pallets bereinforced by a variety of means.

[0006] The below-referenced U.S. patents disclose embodiments that wereat least in-part satisfactory for the purposes for which they wereintended. The disclosures of all the below- referenced prior UnitedStates patents, in their entireties, are hereby expressly incorporatedby reference into the present application for purposes including, butnot limited to, indicating the background of the present invention andillustrating the state of the art.

[0007] U.S. Pat. No. 5,417,167 discloses a plastic shipping pallet ofthe type usually manufactured from wood which is made of hollow plasticstringers and deck boards. The stringers and deck boards are made ofplastic materials that may be either virgin plastic, recycled plasticsor mixes. The stringers and deck boards are hollow but have closed endsto prevent entry of dirt, fluids, insects and vermin. The stringers anddeck boards may be made in a blow molding process or using continuousextrusion and molding processes similar to that used in the manufactureof corrugated pipe. Various connection configurations for affixing thedeck boards to the stringers are described including fixation by screwsas well as interlocking connections between the plastic parts themselvesand the use of separate interlocking components which engage the deckboard and stringers.

[0008] U.S. Pat. No. 5,845,588 discloses a pallet fabricated of athermoplastic material which is produced by joining togetherindividually fabricated structural components, each of which isindividually thermoformed from an extruded plastic parison of amultilayer structure. The structural components include a deck in theform of a continuous sheet with longitudinal and transverse sides, oneor more upper runner components fastened by their top side to the bottomof the deck, each of which includes a cross member with downward-facingposts, and one or more lower runner components, each of which includes across member with upward-facing posts and which is fastened by the topsof its posts to the bottoms of matching posts on the corresponding upperrunner components.

[0009] U.S. Pat. No. 5,868,080 discloses a reinforced plastic palletconstruction and assembly method wherein multiple reinforcing bars areemployed. At least some of the reinforcing bars have an exposed surfaceat a topside surface, underneath surface or underside surface of thepallet. In addition to functioning as a reinforcing member, the exposedsurfaces of the reinforcing bars comprise an anti-skid surface formaintaining positioning of payload on the pallet or facilitatingtransport of the pallet, e.g., via a forklift or automated transportsystem. Various techniques for retaining the reinforcing bars withinchannels formed in the plastic pallet body are described. Thereinforcing bars preferably comprise composite structural members offiberglass reinforced plastic fabricated from a pultrusion process.

[0010] U.S. Pat. No. 6,209,464 discloses a pallet that includes arectangular support deck having a substantially planar upper supportingsurface including a plurality of channels formed therein and extendingacross the pallet. The deck includes support members extending from anunderside of the deck that nest in recesses formed in the upper surfaceof the deck. An alignment portion is formed at a center point along thefirst edge of the deck and a second alignment portion is formed at acenter point of an opposed edge of the deck. The alignment portionincludes angled sides for receiving a tapered member of a complementarydevice.

SUMMARY AND OBJECTS OF THE INVENTION

[0011] It is one object of the present invention to provide alight-weight and compact yet more durable pallet. It is another objectof the invention to use 100% recycled plastic in construction of thepallet to provide a cleaner environment. It is still another object ofthe invention to have a pallet with improved weight to strength ratio.It is yet another object to provide a pallet that is stackable andnestable with other pallets. It another object of the invention toprovide a pallet of varying colors that is inexpensive to produce andeasy to manufacture using largely recycled materials.

[0012] Another object of the invention is to provide a pallet that ismore ruggedized and reliable, thereby decreasing down time and operatingcosts. Another object of the invention is to provide a pallet that hasone or more of the characteristics discussed above but which isrelatively easy to assemble using a minimum of equipment. Another objectof the invention is to provide a process of manufacture that ispredictable and reproducible, thereby decreasing variance and operatingcosts. Another object of the invention is to provide a method that hasone or more of the characteristics discussed above but which isrelatively simple to setup and operate using relatively low skilledworkers.

[0013] In accordance with one aspect of the invention, the inventivepallet system has a pallet body which has a separately formed lower orpallet stabilizing portion (i.e., a first portion) and a separately blowmolded upper or load bearing portion (i.e., a second portion) connectedto the first portion. The pallet body preferably has four recesses forfour-way fork access. The second or upper portion may have a non-sliptopside surface, e.g., a knurled surface. The first portion ispreferably made up of at least one foot which is attached to the secondportion by insert molding, one rail or runner attached to the foot, andone stringer attached to the runner. In one embodiment, the firstportion includes a plurality of feet secondly molded into the second orload bearing portion. The runners preferably have a ridge or protrudingmember for engagement with the foot, and the foot preferably includes achannel for engagement with the load bearing portion. The load bearingand pallet stabilizing portions may be pocketed, have waffleconfiguration, or honeycomb configuration for added weight to strengthratio. The pockets have at least one of the following shapes:triangular, circular, square, oval, rectangular, hexagonal, andoctagonal. The second or load carrying portion may also contain at leastone cavity and/or perimeter lip on a topside surface for receiving apallet stabilizing surface of another pallet in a nesting or stackingarrangement. The feet and the runners are shaped like at least one ofthe following: triangle, square, rectangle, parallelogram, andtrapezoid. Alternatively, the foot is frustoconical or pyramidal shaped.Ribs may also provide attachment of the second upper portion to therunner.

[0014] Other features of the upper or load bearing portion include anend cap to cover the fork receiving recesses, and a cavity cover forcovering the nesting cavities when not in use. The pallet furtherpreferably has at least one handle hole for ease of carrying by a user.The pallet and all of its parts may be constructed of various suitabletypes of moldable materials, such as recycled HDPE plastic, having awide variety of colors.

[0015] The pallet system may further include a load identificationsystem including at least one of the following: bar coding, hotstamping, molding in a logo, affixing a card holder, and tagging withtape, a top cap, and tie members for securing the cap to at least onepallet body.

[0016] In accordance with another aspect of the invention, the inventivemethod of manufacturing a pallet preferably includes the steps ofinserting the pallet stabilizing portion into a mold (such as a plastic,metal or wood rod) and then blow molding around the insert a loadbearing portion. In one embodiment, the method of forming a plasticpallet preferably has the steps of: a) forming a first runner; b)forming a second runner; c) forming a third runner; d) inserting therunners into a mold; e) blow molding a load bearing portion in a mannerwhich engages the runners to form a pallet; f) ejecting the pallet fromthe mold; g) allowing the pallet to cool before stacking them. Therunners may be put into the mold by an automated arm and held in placeby a spring biased or other type of clamp during the blow molding of theload bearing portion. Reinforcing members may also be inserted duringthis process. The members are preferably rolled steel rods that areinserted into channels in the second portion while this portion iscooling.

[0017] These and other aspects and objects of the present invention willbe better appreciated and understood when considered in conjunction withthe following description and the accompanying drawings. It should beunderstood, however, that the following description, while indicatingpreferred embodiments of the present invention, is given by way ofillustration and not of limitation. Many changes and modifications maybe made within the scope of the present invention without departing fromthe spirit thereof, and the invention includes all such modifications.

BRIEF DESCRIPTION OF THE DRAWINGS

[0018] A clear conception of the advantages and features constitutingthe present invention, and of the construction and operation of typicalmechanisms provided with the present invention, will become more readilyapparent by referring to the exemplary, and therefore non-limiting,embodiments illustrated in the drawings accompanying and forming a partof this specification, wherein like reference numerals designate thesame elements in the several views, and in which:

[0019]FIG. 1 is a perspective underside view of one embodiment of thepallet system of the present invention;

[0020]FIG. 2 is a perspective view of the pallet runner shown in FIG. 1of the present invention;

[0021]FIG. 3 is a perspective topside view of FIG. 1 of the presentinvention;

[0022]FIG. 4 is a perspective view of another embodiment of the presentinvention;

[0023]FIG. 5 is a side view of another embodiment of the presentinvention;

[0024]FIG. 6 is a side view of another embodiment of the presentinvention;

[0025]FIG. 7 is a side view of still another embodiment of the presentinvention;

[0026]FIG. 8 is a perspective underside view of another embodiment ofthe pallet of the present invention;

[0027]FIG. 9 is a perspective view of the pallet runner shown in FIG. 8of the present invention;

[0028]FIG. 10 is a perspective topside view of FIG. 8 of the presentinvention;

[0029]FIG. 11 is a perspective topside view of another embodiment of thepresent invention;

[0030]FIG. 12 is a perspective underside view of FIG. 11 of the presentinvention;

[0031]FIG. 13 is a perspective view of another embodiment of the presentinvention;

[0032]FIG. 14 is a perspective underside view of another embodiment ofthe present invention;

[0033]FIG. 15 is a perspective underside view of another embodiment(like FIG. 8) of the present invention including stringers;

[0034]FIG. 16 a cutaway view along A′- A′ of FIG. 1 of the presentinvention;

[0035]FIG. 17 is a cutaway view of the embodiment of FIG. 1 shown in amold;

[0036] FIGS. 18-20 are various perspective views of another embodimentof the pallet runner of the present invention;

[0037]FIG. 21 is a cutaway view (along B′-B′ of the runner of FIG. 20)of still another embodiment of the present invention showing theincorporation of the runner shown in FIGS. 18-20;

[0038] FIGS. 22-26 are cutaway views of other embodiments of the presentinvention showing the connection of the lower portion to the upperportion;

[0039]FIG. 27 is a perspective view of another embodiment of the presentinvention;

[0040]FIG. 28 is a perspective underside view of another embodiment ofthe present invention;

[0041]FIG. 29 is a perspective topside view of the pallet system shownin FIG. 28;

[0042]FIG. 30 shows one embodiment a foot of the pallet system shown inFIGS. 28-29;

[0043]FIG. 31 is a cutaway view along C′-C′ of the embodiment of FIG.29;

[0044]FIG. 32 is a cutaway view of two pallets like the one shown inFIG. 28 nested and stacked;

[0045]FIG. 33 is a perspective topside view of another embodiment of thepresent invention;

[0046]FIG. 33A is a cutaway view along D′-D′ of the embodiment shown inFIG. 33;

[0047]FIG. 34 is a cutaway view along D′-D′ of the embodiment shown inFIG. 33;

[0048]FIG. 35 is a perspective view of another embodiment of the palletsystem present invention;

[0049]FIG. 36 is a perspective view of a pallet mold and one embodimentof the pallet system present invention;

[0050]FIG. 37 is a flowchart illustrating the inventive blow moldingmethod;

[0051]FIG. 38 is a perspective topside view of FIG. 1 includingadditional inserts; FIG. 39 is a perspective topside view of the palletsystem of FIG. 26 including additional inserts; and

[0052]FIG. 40 is a cutaway view along line E′-E′ of FIG. 38.

[0053] In describing the preferred embodiment of the invention, which isillustrated in the drawings, specific terminology will be resorted tofor the sake of clarity. However, it is not intended that the inventionbe limited to the specific terms so selected and it is to be understoodthat each specific term includes all technical equivalents which operatein a similar manner to accomplish a similar purpose. For example, theword “connected” or terms similar thereto are often used. They are notlimited to direct connection but include connection through otherelements where such connection is recognized as being equivalent bythose skilled in the art.

DETAILED DESCRIPTION

[0054] The present invention and the various features and advantageousdetails thereof are explained more fully with reference to thenon-limiting embodiments described in detail in the followingdescription.

[0055] 1. Preferred Embodiments

[0056] As shown in FIG. 1, pallet system 5 contains a body 10 whichincludes an upper or load bearing component or portion 15 and a lower orpallet stabilizing component or portion 20. The upper or second portion15 preferably includes topside surface 18 and underside surface 19 on atop deck 21. The lower or first portion 20 may include several feetand/or rails or runners attached thereto. For example, at each of thefour comers a first foot 35, a second foot 38, a third foot 39, and afourth foot 40 may be either integrally or separately formed into thetop deck 21. In the preferred embodiment, at least two rails, a firstrail or runner 25 and a second rail or runner 30, are then eitherintegrally or separately connected to the feet 35, 38, 39 and 40.Additional rails or runners may be added for additional strength andadditional feet may be added as well (see, e.g., FIGS. 5-10). One runneris typically 48 inches long and about 3 inches high. As shown in FIGS.8-10, additional feet 43, 44, 46 of different sizes may also be present.The deck is preferably 1½ inches thick making the entire pallet lessthan 5 inches tall. The rails or runners 25, 30 and feet may beseparately formed as individual parts (see FIG. 2) or may be molded intoan upper half 47 and a lower half 48 as shown in the embodiment at FIG.4. These pieces are separately blow-molded then they may be insertmolded to join them to the opposite half. Alternatively, the feet andrails may be formed by injection molding, rotomolding, winding,thermoforming, etc. In this embodiment, the feet 35, 40 are formed fromfirst foot portion 35a, 40a and second foot portion 35b, 40b. The firstportions 35a and 40a are preferably connected by an upper rail 49.Although not shown, a similar structure may be utilized for other feetand runners. For example, if the upper half 47 is first blow molded, itmay be inserted into another mold and the bottom half 48 is then newlyblow molded in such a way so that the two pieces 47, 48 become connectedthrough the blow molding process. In the same way, upper half 47 andlower half 48 shown in FIG. 4 may be blow molded to the top deck 21.Alternatively, upper half 47 may actually be initially integrally blowmolded as part of the deck 21. In this embodiment the half 47 may be inthe lower half of the part mold while the deck may be in the upper halfof the part mold. After the pieces have been combined through the insertmolding process, they form the body 10 of the pallet system 5. Forexample, once the upper half 47 and lower half 48 are blow moldedtogether, the combined pieces may be inserted into a new mold and thesecond upper portion 15 may be blow molded around them.

[0057] As shown in the embodiments shown in FIGS. 5, 6 and 7, there aremany variations on the pallet foot and rail structure. In addition,another foot 42 or series of feet may be added to provide morestructural rigidity. For example, a bottom deck 22 may be separately orintegrally blow molded into the top deck and rails to create theembodiment shown in FIG. 5. Alternatively, it is possible that aplurality of feet 35, 40, 42 are inserted into a mold and the top deck21 will be blow molded around them as shown in the embodiment in FIG. 6.Also possible is the embodiment shown in FIG. 7 in which thetriangular-shaped feet 35, 40, 42 are separately blow molded and then atop deck 21 with feet is blow molded around them, totally encapsulatingthe first molded feet through the insert molding process.

[0058] It will be apparent to one of ordinary skill in the art that theaddition of feet and/or rails will further make the pallet 5 structurestronger. Thus, the embodiments shown in FIGS. 8-10 and 11-12, have ninefeet and three runners. As shown in FIG. 11, this embodiment preferablyalso has first cavity 50, a second cavity 52, and a third cavity 55 toreceive the runners and/or feet when similar pallets 5 must be stackedfor storage. The depths of the cavities may vary depending on a varietyof factors such as thickness of the plastic and the dimensions of thefeet and/or runners. The embodiment in FIG. 11 is known as a four- waypallet because the forks (not shown) of a fork lift (not shown) can beinserted into the pallet in four different directions A, B, C, D. Thepallet preferably, as shown in FIG. 11, has recesses (60, 61, 62, 63,64, 65, 66 and 67) for receiving the forks. The recesses 60-67 may varyin depth and width depending on the type of pallets and may also vary innumber. For example, like in FIG. 1, in the embodiment shown in FIG. 11there are four areas for the fork to enter in this four-way pallet.Alternatively, pallet 5 may be a two-way pallet as shown in the FIG. 13and thus it will have fewer recesses.

[0059] As shown in FIGS. 12 and 13, pockets may be incorporated into thedesign of the second or upper portion 15 and the first or lower portion20 to add strength and/or reduce weight. Such honeycomb or waffledesigns are often used when molding plastics. The pockets 70 may vary indimensions and shape (e.g., triangles 70a or circles 70b). The pockets72 on the lower portion 20 may also vary in dimension and shape. Theembodiment shown in FIG. 12, the pockets 72 may also serve to give thelower portion 20 an anti-skid underside surface 75 so the pallet 5 doesnot slip off the forks. However, this may also be done by merely theaddition of knobs, knurling, a rubberized coating and/or rubbergrommets. The topside surface (not shown) of the lower portion may alsobe pocketed. As shown in the embodiment in FIG. 13, at least one, heretwo, metal rods 78a, 78b may be insert molded into the pallet 5. One wayof doing this is by laying the rods into the mold and then blow moldingthe pallet around them. Another way is to push these in prior to thesecond portion's cooling. These reinforcing rods 78 a, 78 b may also beconstructed of wood or more dense and/or stronger plastic.

[0060] In the embodiments shown in FIGS. 14-15, at least one stringer(e.g., 82) may be attached to the rails 25, 30, 32 to add additionalstrength and stability to the pallet 5. In the embodiment shown in FIG.14, a first stringer 80, a second stringer 82, and a third stringer 83connect to the rails 25, 30, and 32. Again, the insert blow moldingprocess can be used to connect the stringers 80, 82 and 83 to the rails25, 30, 32. Alternatively, a post molding process may be used where theplastic or metal stringer is inserted prior to the runners cooling.

[0061] As shown in FIGS. 16-21, the second portion 15 and/or firstportion 20 may have either ribs 85 or ridges 90 and channels 88 or holes92 to engage each other during the insert blow molding process. Forexample in FIG. 16, the second or upper portion 15 contains channels 88,88 a, 88 b which are engaged by protruding ridges 90 in the runner 25.Kiss off 84 helps to further connect runner 25 to the top deck 21 as therunner's crown 87 is pressed against the kiss off 84. Within the firstmold half 81 a and the second mold half 81 b (see, e.g., FIG. 17). Thisalso helps to strengthen that point.

[0062] In FIGS. 18-21, a protruding member 90 and rib 85 is received inhole 92 and channel 88, respectively. In this embodiment, first the rail30, rib 85, and protruding member 90 are blow molded. The rib andprotruding member preferably run the length of the rail. Then they areset into a cavity in a mold for a second or upper portion 15 to beinsert blow molded into connection with the second portion 15. A lip 89and groove may also be employed as well. This deep draw molding processstrengthens the connection between the portions 15, 20. In oneembodiment 20 is about 0.25 inches thick. A combination of theseinterconnections (e.g., 85, 88, 89, 90, 92) and/or heating help attachthe rails 30 to the second portion 15.

[0063] In FIGS. 22-26, channel 88 is molded into the portion 15 and aprotruding member 90 from the rail 25 is insert blow molded intoconnection on portion 15. A ridge 85 engages a lip 89 for betterconnection. Variation on the same theme is shown in FIG. 25, wherein achannel 88 is created in the first portion 20 and during the insert blowmolded process a foot 35 having a protruding member 90 is blow moldedinto the first portion 20. As shown in FIG. 26, second upper portion 15has a protruding member 93 which is insert molded into a cavity 96 in afoot 40.

[0064] As shown in FIG. 27, this embodiment has additional holes orrecesses bore through rectangular-shaped runners. The recesses are forreceiving the lifting tines of a forklift. When not in use, an end cap95 may be used to block the recesses 62-65 in the first portion 20. Theend cap 95 may limit entry on one or more sides of the pallet 5. Thismay keep vermin out from underneath the pallet and/or limit access bythe forks of the forklift. In the embodiment shown in FIG. 27, one ormore cavity covers 100 may also be employed to cover the cavities 52-55on the second upper portion 15. As indicated previously, these cavitiesnormally receive a foot (not shown) and/or a runner (not shown) ofanother pallet while nested. Cavity covers may be used to also keep outvermin or other materials and provide further stability to the top deck21 of the pallet. These covers (100) are generally flush with thetopside surface 18 so that loads do not get hung up. A recess and a lipmay be added to the cover and the cavity for a tighter fit. A handlehole 105 may also be provided in at least one or more positions on thepallet 5 to allow for easy handling and caring by a warehouse worker. Itis important to note that all the various holes, recess, and cavitiescan be configured and arranged in a blow-molded plastic pallet todecrease weight and increase strength.

[0065] FIGS. 28-32, show another more lightweight embodiment of the blowmolded pallet system of the present invention. Again this pallet system305, has a body 310 including a lower or first portion 320 and upper orsecond portion 315. A deck 321 is on the top of the second portion 320and has a topside surface 318 and an underside surface 319. As bestshown in FIG. 30, this embodiment preferably has individual hollow feet335 which collectively form the first or lower portion 320. As shown inFIG. 31, a deep draw blow molding process may also be used tomanufacture this embodiment. Again the deep draw process incorporatesthe first portion 320 into the second portion 315. This embodiment alsoallows for interlocking of the protruding members 390 into holes 392.FIG. 32 shows how several pallets, e.g., 305A and 305B of this type canbe nested and stacked together as the feet, e.g., 335A, 335B of thedifferent pallets 305A, 305B fit into each other.

[0066]FIGS. 33, 33A, 34 show an embodiment of another lighter weight(e.g., less than 25 pounds) blow molded pallet system 405. This palletis preferably 40 inches wide, 48 inches long, and 4.5 inches high. Apallet body 410 of the pallet system 405 may be blow molded as a singlepiece and then an insert, e.g., a tube or rod 413 may be inserted intothe body 410 along a channel 416 after the molding is complete but thepallet is still warm. As the pallet cools, the plastic may furthershrink around the rod. This is sometimes referred to as post molding.The insert is preferably about 40 inches long and is fabricatedseparately from plastic, metal or, wood. Alternatively, the insert maybe placed into the pallet body mold and the body is then blow moldedaround it. One or more inserts may be used to increase the strength ofthe pallet system. If the insert 413 is not plastic, the insert shouldbe removed before the pallet body is ground up during the recyclingprocess. As shown in FIG. 33A, one or more kiss offs 384 may beincorporated in the pallet body 310 design to add strength.

[0067]FIG. 35 shows stacked pallets nested and tied together with astrap or tie 110 and a top cap 115. The top cap 115 preferably has atleast one metal reinforcing member 120 insert molded therein to retainthe tie 110. One or more pallets may have a load identification system125 as shown. FIG. 35 shows nested or stacked pallets 5 with a perimeterlip 130. Foot 38 engages lip 130. The tie 110 preferably is insertedthrough a hole 150 found in the pallet body deck (see FIG. 1). The hole150 may be formed during molding. In one embodiment the hole may beformed on an outer ledge and compression molding may be used toreinforce the ledge.

[0068] Suitable materials for producing the inventive plastic palletinclude virgin or recycled polyolefins, polyethylene (PE), polyvinylchloride (PVC), acrylonitrile butadiene styrene (ABS) plastics,polypropylene, polyamides (PA), and polycarbonates (PC) of one or morecolors. The preferred embodiments are made of 100% reground and recycledultrahigh molecular weight high-density polyethylene (HDPE - UHMW).Polypropylene homopolymer, or polypropylene block copolymer may also beused for the various parts of the pallet body. Another material whichmay be blended in is polyvinyl toluene (PVT) or some other polyvinyl. Asuitable friction material may be selected from polyolefins containingmaterials like LLDPE, TPE, EVA, EEA and the like to stop things fromsliding off the topside surface 18 of the pallet or to further addfriction to the underside of the first portion of the pallet. Otherpossible options are Duraprene, neoprene, or virgin rubber.

[0069] In addition to the high-friction materials listed above, palletsystem 5 can also include a number of inserts 500 as shown in FIGS. 38and 39. Each insert is formed of a high-friction material that is ablend of a hard plastic and a rubber, such that the insert 500 is formedto not only be a high-friction material but also to be somewhatdeflectable in order to maintain the inert 500 in contact with an object(not shown) positioned on the pallet 5 as the object moves on the pallet5. The blend of materials utilized to form the inserts 500 may be ablend of 50% w/w rubber and 50% w/w of the plastic material, but ispreferably a blend of less than 50% w/w rubber and greater than 50% w/wplastic material, with a particularly preferred blend composition being20% w/w rubber and 80% w/w plastic material. The plastic materials whichcan be utilized in forming the blend for the inserts are the sameplastic materials listed above, namely, LLDPE, TPE, EVA, EEA and othersuitable materials, with a low density polyethylene (linear ornon-linear) being especially preferred. Depending upon the particularproperties desired for the inserts 500, the weight percentage of theplastic material can be varied to provide more or less overall rigidityto the inserts 500 in accordance with the particular use to which thepallet 5 including the inserts 500 is to be put. Such materials aretypically first heated in separate tanks then mixed in a blender beforebeing extruded by an extrusion machine connected to the production line.

[0070] The inserts 500 are formed in a conventional injection moldingprocedure whereby the selected blend used to form the inserts 500 isinjected into the mold to form the inserts 500 having the desired shape.As shown in FIGS. 38 and 39, the inserts 500 are preferably circular inshape, but may also have any other desired shape in order to accommodatethe particular use for or shape of the pallet system 5.

[0071] Once the inserts 500 are fully formed and cooled, they areattached to the pallet system 5. Each insert 500 can be moldedintegrally with the pallet system 5, or may be attached to the palletsystem 5 in a post-molding procedure. Also, while the inserts 500 aredisclosed as being attached to the topside surface 18 of the upperportion 15, the inserts 500 may also be present on and secured to thelower portion, i.e., the feet 35, 38, 39 and 40, and/or the runners 25and 30 secured to the underside surface 19 to assist the lower portion20 in gripping the surface on which the pallet 5 is placed.

[0072] When the inserts 500 are integrally formed with the pallet system5, the inserts 500 are positioned within a mold (not shown) in which theupper portion 15 is to be formed. The inserts 500 are positioned wheredesired within the mold such that the resulting upper portion 15 isformed with the inserts 500 positioned at the desired locations. Thus,when the material used to form the upper portion 15 is expanded withinthe molds to conform to the shape of the mold, the material alsocontacts and surrounds the inserts 500 in order to fix and maintain theposition of the insert 500 with respect to the upper portion 15. Morespecifically, as the upper portion 15 cools, the material forming theupper portion 15 adheres to and hardens around the insert 500 to holdthe insert in engagement with the upper portion 15.

[0073] Alternatively, the mold in which the upper portion 15 is formedcan be shaped to include features (not shown), which create recesses(not shown) in the topside surface 18 in which the inserts 500 can bepositioned after formation of the upper portion 15. In this procedure,after the upper portion 15 has been initially formed within the mold,the mold is opened and the inserts 500 are positioned within therecesses (not shown) formed in the topside surface 18 of upper portion15 by the features within the mold. After the inserts 500 are positionedwithin the recesses, the upper portion 15 cools, and consequentlyshrinks, fixedly engaging each of the inserts 500 to hold the inserts500 in position on the topside surface 18.

[0074] When the inserts 500 are to be positioned on the lower portion20, i.e., on the feet or the runners, the processes for attaching theinserts 500 to these components is performed identically to either ofthe processes outlined above for securing the inserts 500 to the upperportion 15. More specifically, in each case, the inserts 500 arepositioned within the molds for these components, or secured to thelower portion 20, feet or runners immediately after formation within themold as in the above-recited methods. Also, the inserts 500 can bepositioned on both of the upper portion 15 and lower portion 20, tofurther enhance the non- slip capabilities of the pallet system 5 withrespect to both the objects positioned on the pallet system 5, and thesurface on which the pallet system 5 is positioned.

[0075] To further assist the inserts 500 in engaging the objects placedon the upper portion 15, as best shown in FIG. 40, the upper portion 15can be formed such that the topside surface 18 curves upwardly from eachside of the surface 18 towards the center of the surface 18. Preferably,this curvature is parabolic in shape and enables the topside surface 18and upper portion 15 to flex when objects are positioned on the surface18. This shape also allows the pallet 5 to deflect during use in adirection that does not result in deformation of the pallet 5 and alsoincreases the useful life of the pallet 5 due to the inherent bias inthe curved upper portion 15 acting oppositely to the weight of theobjects positioned on the pallet 5.

[0076] 2. In Use and Operation

[0077] As indicated above, in the preferred embodiment there may be oneor more molds which independently and separately form (e.g., blow-mold)feet, runners and stringers. As shown in FIG. 36, there is alsopreferably a mold 81 having two halves 81a and 81b which separately blowmolds a second or upper portion, and a first portion. In the preferredembodiment, the second upper portion and first portion molds have aposition for receiving feet, runners 25, 30, and/or stringers.Typically, each mold is constructed of a right half 81 a and left half81 b. The inventors envision one mold form could be developed tomanufacture heavy-duty, medium-duty, and light-duty pallets. The numberof preformed inserts added to this mold form would thus determine thepallet's lift capacity and usage.

[0078] As illustrated in FIG. 37, the separately formed (200) pieces(e.g., feet, runners, etc.) are then inserted (210) into the deckportion mold and the deck portion is blow molded into or around thefeet, stringers, and/or the rails (220). In one embodiment, gravityholds the inserts (e.g., the feet, runners, rods and stringers, etc.) inplace during the blow molding of the deck. In another embodiment, pinsthat may be tensioned or spring biased hold the feet, stringers, and/orrunners in place in the deck mold. Because the insert molding processadds steps and time to the molding of the pallet, automating the stepscan help reduce the impact of these factors. Also, automation increasesreproducibility and thus quality control.

[0079] After the pallet is completely formed, it is ejected (230) fromthe mold and allowed to cool (240). In one preferred embodiment, themold for the deck has the flexibility to receive either one or aplurality of rails and/or feet depending on the type of pallet requestedby the customer. For example, Customer Al may only want a pallet with atop deck, four feet, and a bottom deck, while Customer B2 may want apallet with a top deck, six feet, and three runners. These first portionpieces may all be first independently molded and then inserted into alarger mold so that the inserts may be blow molded together with thedeck portion to form the complete pallet end product requested by thecustomer. Alternatively, for example, a blow molded bottom deck may beadded later while still warm by affixing it to the feet by some meanssuch as an adhesive, a channel/protruding member combination, ascrew/fastener or some other means.

[0080] It is also possible with the insert molding process describedherein to make the upper portion 15 of a first material and the lowerportion 20 of a second material. If differing blends of rubber and/orplastic are used, a swap out or “returnable” recycling program may benecessary so that these blends are not accidentally blended withstraight HDPE for example.

[0081] The preferred heavy-duty pallet weighs less than 50 pounds, isrelative inexpensive (e.g., >$50), and can handle loads up to 3500pounds. Pallets made with blended rubber may be heavier and more costly.

[0082] The individual components described herein need not necessarilybe formed in the disclosed shapes, or assembled in the disclosedconfiguration, but could be provided in virtually any shape, andassembled in virtually any configuration. Further, although the feet andrunners are described herein as physically separate modules, it will bemanifest that it may be more fully integrated into the deck portions.Furthermore, all the disclosed features of each disclosed embodiment canbe combined with, or substituted for, the disclosed features of everyother disclosed embodiment except where such features are mutuallyexclusive. Finally, it is intended that the appended claims cover allsuch additions, modifications and rearrangements. Expedient embodimentsof the present invention are differentiated by the appended subclaims.

What is claimed is:
 1. A pallet comprising: a) a first component formedin a first blow molding operation; b) a second component formed in asecond blow molding operation, the second component engaged with thefirst component during the second operation; and c) at least one insertpositioned in at least partially exposed configuration on one of thefirst component or the second component.
 2. The pallet of claim 1wherein at least one insert is formed of a generally rigid material. 3.The pallet of claim 2 wherein the generally rigid material is a blend ofa hard plastic material and a rubber.
 4. The pallet of claim 3 whereinthe blend is at least 50% of weight of the hard plastic material.
 5. Thepallet of claim 3 wherein the hard plastic material is polyethylene. 6.The pallet of claim 3 wherein the first component is formed a generallyrigid material.
 7. The pallet of claim 1 wherein the second component isformed of a generally rigid material.
 8. The pallet of claim 1 furthercomprising: a) at least one first insert positioned on the firstcomponent; and b at least one second insert positioned on the secondcomponent.
 9. The pallet of claim 1 wherein at least one insert isgenerally circular in shape.
 10. The pallet of claim 1 furthercomprising a third component formed in a third blow molding operationand secured to the second component at a location spaced from the firstcomponent in the second blow molding operation.
 11. The pallet of claim10 further comprising at least one reinforcing member secured betweenthe first component and the third component.
 12. The pallet of claim 1wherein the second component is generally non-planar in shape.
 13. Thepallet of claim 12 wherein the second component is generally parabolicin shape.
 14. A pallet comprising: a) a first component formed in afirst blow molding operation; and b) a second component formed in asecond blow molding operation, the second component engaged with thefirst component during the second blow molding operation, wherein atleast one of the first component and the second component is formed ofthe blend of a hard plastic material and a rubber.
 15. A method forforming a pallet, the method comprising the steps of: a) forming a firstcomponent in a first blow molding process; b) positioning the firstcomponent in a mold for a second component; c) placing at least oneinsert within the mold for the second component; and d) forming a secondcomponent in engagement with the first component and the at least oneinsert in a blow molding process.
 16. The method of claim 15 wherein theat least one insert is formed of a blend of a hard plastic material anda rubber.
 17. The method of claim 15 wherein the first component isformed of a hard plastic material and a rubber.
 18. The method of claim15 wherein the second component is formed of a blend of a hard plasticmaterial and a rubber.
 19. A method for forming a pallet, the methodcomprising the steps of: a) placing at least one insert in a mold for afirst component; b) forming the first component in engagement with theat least one insert in a first blow molding process; c) positioning thefirst component in a mold for a second component; and d) forming thesecond component in engagement with the first component.
 20. The methodof claim 19 further comprising the step of placing a second insert inthe mold for the second component prior to forming the second component.